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path: root/drivers/mtd/nand/docg4.c
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Diffstat (limited to 'drivers/mtd/nand/docg4.c')
-rw-r--r--drivers/mtd/nand/docg4.c118
1 files changed, 76 insertions, 42 deletions
diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c
index 799da5d1c85..ce24637e14f 100644
--- a/drivers/mtd/nand/docg4.c
+++ b/drivers/mtd/nand/docg4.c
@@ -44,6 +44,26 @@
#include <linux/mtd/nand.h>
#include <linux/bch.h>
#include <linux/bitrev.h>
+#include <linux/jiffies.h>
+
+/*
+ * In "reliable mode" consecutive 2k pages are used in parallel (in some
+ * fashion) to store the same data. The data can be read back from the
+ * even-numbered pages in the normal manner; odd-numbered pages will appear to
+ * contain junk. Systems that boot from the docg4 typically write the secondary
+ * program loader (SPL) code in this mode. The SPL is loaded by the initial
+ * program loader (IPL, stored in the docg4's 2k NOR-like region that is mapped
+ * to the reset vector address). This module parameter enables you to use this
+ * driver to write the SPL. When in this mode, no more than 2k of data can be
+ * written at a time, because the addresses do not increment in the normal
+ * manner, and the starting offset must be within an even-numbered 2k region;
+ * i.e., invalid starting offsets are 0x800, 0xa00, 0xc00, 0xe00, 0x1800,
+ * 0x1a00, ... Reliable mode is a special case and should not be used unless
+ * you know what you're doing.
+ */
+static bool reliable_mode;
+module_param(reliable_mode, bool, 0);
+MODULE_PARM_DESC(reliable_mode, "pages are programmed in reliable mode");
/*
* You'll want to ignore badblocks if you're reading a partition that contains
@@ -113,6 +133,7 @@ struct docg4_priv {
#define DOCG4_SEQ_PAGEWRITE 0x16
#define DOCG4_SEQ_PAGEPROG 0x1e
#define DOCG4_SEQ_BLOCKERASE 0x24
+#define DOCG4_SEQ_SETMODE 0x45
/* DOC_FLASHCOMMAND register commands */
#define DOCG4_CMD_PAGE_READ 0x00
@@ -122,6 +143,8 @@ struct docg4_priv {
#define DOC_CMD_PROG_BLOCK_ADDR 0x60
#define DOCG4_CMD_PAGEWRITE 0x80
#define DOC_CMD_PROG_CYCLE2 0x10
+#define DOCG4_CMD_FAST_MODE 0xa3 /* functionality guessed */
+#define DOC_CMD_RELIABLE_MODE 0x22
#define DOC_CMD_RESET 0xff
/* DOC_POWERMODE register bits */
@@ -190,17 +213,20 @@ struct docg4_priv {
#define DOCG4_T 4 /* BCH alg corrects up to 4 bit errors */
#define DOCG4_FACTORY_BBT_PAGE 16 /* page where read-only factory bbt lives */
+#define DOCG4_REDUNDANT_BBT_PAGE 24 /* page where redundant factory bbt lives */
/*
- * Oob bytes 0 - 6 are available to the user.
- * Byte 7 is hamming ecc for first 7 bytes. Bytes 8 - 14 are hw-generated ecc.
+ * Bytes 0, 1 are used as badblock marker.
+ * Bytes 2 - 6 are available to the user.
+ * Byte 7 is hamming ecc for first 7 oob bytes only.
+ * Bytes 8 - 14 are hw-generated ecc covering entire page + oob bytes 0 - 14.
* Byte 15 (the last) is used by the driver as a "page written" flag.
*/
static struct nand_ecclayout docg4_oobinfo = {
.eccbytes = 9,
.eccpos = {7, 8, 9, 10, 11, 12, 13, 14, 15},
- .oobavail = 7,
- .oobfree = { {0, 7} }
+ .oobavail = 5,
+ .oobfree = { {.offset = 2, .length = 5} }
};
/*
@@ -244,7 +270,7 @@ static int poll_status(struct docg4_priv *doc)
*/
uint16_t flash_status;
- unsigned int timeo;
+ unsigned long timeo;
void __iomem *docptr = doc->virtadr;
dev_dbg(doc->dev, "%s...\n", __func__);
@@ -252,22 +278,18 @@ static int poll_status(struct docg4_priv *doc)
/* hardware quirk requires reading twice initially */
flash_status = readw(docptr + DOC_FLASHCONTROL);
- timeo = 1000;
+ timeo = jiffies + msecs_to_jiffies(200); /* generous timeout */
do {
cpu_relax();
flash_status = readb(docptr + DOC_FLASHCONTROL);
- } while (!(flash_status & DOC_CTRL_FLASHREADY) && --timeo);
-
+ } while (!(flash_status & DOC_CTRL_FLASHREADY) &&
+ time_before(jiffies, timeo));
- if (!timeo) {
+ if (unlikely(!(flash_status & DOC_CTRL_FLASHREADY))) {
dev_err(doc->dev, "%s: timed out!\n", __func__);
return NAND_STATUS_FAIL;
}
- if (unlikely(timeo < 50))
- dev_warn(doc->dev, "%s: nearly timed out; %d remaining\n",
- __func__, timeo);
-
return 0;
}
@@ -469,7 +491,7 @@ static uint8_t docg4_read_byte(struct mtd_info *mtd)
return status;
}
- dev_warn(doc->dev, "unexpectd call to read_byte()\n");
+ dev_warn(doc->dev, "unexpected call to read_byte()\n");
return 0;
}
@@ -611,6 +633,14 @@ static void write_page_prologue(struct mtd_info *mtd, uint32_t docg4_addr)
dev_dbg(doc->dev,
"docg4: %s: g4 addr: %x\n", __func__, docg4_addr);
sequence_reset(mtd);
+
+ if (unlikely(reliable_mode)) {
+ writew(DOCG4_SEQ_SETMODE, docptr + DOC_FLASHSEQUENCE);
+ writew(DOCG4_CMD_FAST_MODE, docptr + DOC_FLASHCOMMAND);
+ writew(DOC_CMD_RELIABLE_MODE, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ }
+
writew(DOCG4_SEQ_PAGEWRITE, docptr + DOC_FLASHSEQUENCE);
writew(DOCG4_CMD_PAGEWRITE, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
@@ -691,6 +721,15 @@ static void docg4_command(struct mtd_info *mtd, unsigned command, int column,
break;
case NAND_CMD_SEQIN:
+ if (unlikely(reliable_mode)) {
+ uint16_t g4_page = g4_addr >> 16;
+
+ /* writes to odd-numbered 2k pages are invalid */
+ if (g4_page & 0x01)
+ dev_warn(doc->dev,
+ "invalid reliable mode address\n");
+ }
+
write_page_prologue(mtd, g4_addr);
/* hack for deferred write of oob bytes */
@@ -833,7 +872,7 @@ static int docg4_read_oob(struct mtd_info *mtd, struct nand_chip *nand,
return 0;
}
-static void docg4_erase_block(struct mtd_info *mtd, int page)
+static int docg4_erase_block(struct mtd_info *mtd, int page)
{
struct nand_chip *nand = mtd->priv;
struct docg4_priv *doc = nand->priv;
@@ -877,6 +916,8 @@ static void docg4_erase_block(struct mtd_info *mtd, int page)
write_nop(docptr);
poll_status(doc);
write_nop(docptr);
+
+ return nand->waitfunc(mtd, nand);
}
static int write_page(struct mtd_info *mtd, struct nand_chip *nand,
@@ -979,16 +1020,15 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
struct docg4_priv *doc = nand->priv;
uint32_t g4_addr = mtd_to_docg4_address(DOCG4_FACTORY_BBT_PAGE, 0);
uint8_t *buf;
- int i, block, status;
+ int i, block;
+ __u32 eccfailed_stats = mtd->ecc_stats.failed;
buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
read_page_prologue(mtd, g4_addr);
- status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);
- if (status)
- goto exit;
+ docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);
/*
* If no memory-based bbt was created, exit. This will happen if module
@@ -1000,6 +1040,20 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
if (nand->bbt == NULL) /* no memory-based bbt */
goto exit;
+ if (mtd->ecc_stats.failed > eccfailed_stats) {
+ /*
+ * Whoops, an ecc failure ocurred reading the factory bbt.
+ * It is stored redundantly, so we get another chance.
+ */
+ eccfailed_stats = mtd->ecc_stats.failed;
+ docg4_read_page(mtd, nand, buf, 0, DOCG4_REDUNDANT_BBT_PAGE);
+ if (mtd->ecc_stats.failed > eccfailed_stats) {
+ dev_warn(doc->dev,
+ "The factory bbt could not be read!\n");
+ goto exit;
+ }
+ }
+
/*
* Parse factory bbt and update memory-based bbt. Factory bbt format is
* simple: one bit per block, block numbers increase left to right (msb
@@ -1019,7 +1073,7 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
}
exit:
kfree(buf);
- return status;
+ return 0;
}
static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)
@@ -1038,7 +1092,6 @@ static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)
struct nand_chip *nand = mtd->priv;
struct docg4_priv *doc = nand->priv;
struct nand_bbt_descr *bbtd = nand->badblock_pattern;
- int block = (int)(ofs >> nand->bbt_erase_shift);
int page = (int)(ofs >> nand->page_shift);
uint32_t g4_addr = mtd_to_docg4_address(page, 0);
@@ -1053,9 +1106,6 @@ static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)
if (buf == NULL)
return -ENOMEM;
- /* update bbt in memory */
- nand->bbt[block / 4] |= 0x01 << ((block & 0x03) * 2);
-
/* write bit-wise negation of pattern to oob buffer */
memset(nand->oob_poi, 0xff, mtd->oobsize);
for (i = 0; i < bbtd->len; i++)
@@ -1065,8 +1115,6 @@ static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)
write_page_prologue(mtd, g4_addr);
docg4_write_page(mtd, nand, buf, 1);
ret = pageprog(mtd);
- if (!ret)
- mtd->ecc_stats.badblocks++;
kfree(buf);
@@ -1190,8 +1238,7 @@ static void __init init_mtd_structs(struct mtd_info *mtd)
nand->block_markbad = docg4_block_markbad;
nand->read_buf = docg4_read_buf;
nand->write_buf = docg4_write_buf16;
- nand->scan_bbt = nand_default_bbt;
- nand->erase_cmd = docg4_erase_block;
+ nand->erase = docg4_erase_block;
nand->ecc.read_page = docg4_read_page;
nand->ecc.write_page = docg4_write_page;
nand->ecc.read_page_raw = docg4_read_page_raw;
@@ -1313,7 +1360,6 @@ static int __init probe_docg4(struct platform_device *pdev)
struct nand_chip *nand = mtd->priv;
struct docg4_priv *doc = nand->priv;
nand_release(mtd); /* deletes partitions and mtd devices */
- platform_set_drvdata(pdev, NULL);
free_bch(doc->bch);
kfree(mtd);
}
@@ -1325,7 +1371,6 @@ static int __exit cleanup_docg4(struct platform_device *pdev)
{
struct docg4_priv *doc = platform_get_drvdata(pdev);
nand_release(doc->mtd);
- platform_set_drvdata(pdev, NULL);
free_bch(doc->bch);
kfree(doc->mtd);
iounmap(doc->virtadr);
@@ -1342,18 +1387,7 @@ static struct platform_driver docg4_driver = {
.remove = __exit_p(cleanup_docg4),
};
-static int __init docg4_init(void)
-{
- return platform_driver_probe(&docg4_driver, probe_docg4);
-}
-
-static void __exit docg4_exit(void)
-{
- platform_driver_unregister(&docg4_driver);
-}
-
-module_init(docg4_init);
-module_exit(docg4_exit);
+module_platform_driver_probe(docg4_driver, probe_docg4);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mike Dunn");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 14:20:24 +0000